Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K17/00—Soil-conditioning materials or soil-stabilising materials
  • C09K17/14—Soil-conditioning materials or soil-stabilising materials containing organic compounds only
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K17/00—Soil-conditioning materials or soil-stabilising materials
  • C09K17/14—Soil-conditioning materials or soil-stabilising materials containing organic compounds only
  • C09K17/16—Soil-conditioning materials or soil-stabilising materials containing organic compounds only applied in a physical form other than a solution or a grout, e.g. as platelets or granules
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K17/00—Soil-conditioning materials or soil-stabilising materials
  • C09K17/14—Soil-conditioning materials or soil-stabilising materials containing organic compounds only
  • C09K17/18—Prepolymers; Macromolecular compounds
  • C09K17/32—Prepolymers; Macromolecular compounds of natural origin, e.g. cellulosic materials
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
  • E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
  • E21D9/001—Improving soil or rock, e.g. by freezing; Injections
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
  • E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
  • E21D9/06—Making by using a driving shield, i.e. advanced by pushing means bearing against the already placed lining
  • E21D9/0642—Making by using a driving shield, i.e. advanced by pushing means bearing against the already placed lining the shield having means for additional processing at the front end
  • E21D9/0678—Adding additives, e.g. chemical compositions, to the slurry or the cuttings
  • E21D9/0685—Foaming agents
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
  • E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
  • E21D9/10—Making by using boring or cutting machines

Definitions

• the present invention relates to the use of foaming additives in liquid, paste or powder form to condition soil excavated with a tunnel boring machine.
• Said additives can be classified as readily biodegradable and are characterised by a lower ecotoxicological impact than commercial products.
• the first method involves cyclical application of the operations described below:
• Said method is based on eliminating the right portion of rock so as to redistribute forces around the excavation, resulting in the “arch effect”, which partly supports the consolidating action of the reinforcing rods and shotcrete.
• the second construction technique can be divided into two main categories: the partial-face system and the full-face system (which involves excavating the entire tunnel diameter at the same time).
• the first case operations proceed as already described for the conventional method with roadheaders and rock breakers (instead of explosive), gradually forming the shape of the tunnel which will subsequently be lined with reinforced concrete.
• the advance is effected with a complex machine called a Tunnel Boring Machine (TBM), also known as a “mole” which, as well as performing the excavation, supports and prevents collapses of the face, carries away muck (by means of a screw and a conveyor belt), and places the final tunnel lining, consisting of prefabricated reinforced concrete segments.
• TBM Tunnel Boring Machine
• This type of machine can excavate nearly all types of geological material, including compact rock (hard-rock TBM), fractured rock (double-shield TBM), loose soil and under aquifers (EPB—Earth Pressure Balance machine).
• a TBM consists of:
• the cutterhead is fitted with tools called cutters, namely steel discs, which are designed to demolish the soil.
• Scrapers convey the soil to the conveyor belt that carries it out of the tunnel.
• the advance must take place with the excavation chamber constantly and completely full of suitably conditioned excavated material, in order to guarantee homogenous, uniform distribution of soil pressure on the tunnel face and prevent pressure drops between one push and the next.
• Said machines operate well when the layers through which the tunnel is driven are relatively hard and rigid, but do not perform so well when soft, friable soils are excavated.
• One technique used to overcome this problem is to apply a conditioning agent to the soil through the cutterhead. This stabilises the soil and facilitates excavation and soil extraction.
• a standard foaming agent formulation comprises a foaming agent and a stabilising agent.
• the foam is directly injected into the cutterhead at the excavation interface.
• the excavated soil is thus characterised by an organic content, deriving from the use of said additives, which interferes with the ecosystem.
• the foaming products generally used contain anionic surfactants.
• Said anionic surfactants are usually C12-16 alcohol ethoxylate (1-4 ethoxylation groups) sulphates. They are salified organic compounds, generally as sodium salts.
• foaming additives available on the market are:
• Polyfoamer ECO 100 comprising 10 to 20% by weight of a mixture of linear alcohols with a C12-C14 alkyl ethoxylate chain, sulphonated and salified with sodium.
• EP 1027528 illustrates a boring method wherein the composition of the aqueous material injected into the tunnel face consists of a polyethylene oxide with a molecular weight ranging between 2 and 8 million and an anionic surfactant containing sulphate.
• U.S. Pat. No. 6,172,010 discloses an aqueous foaming additive consisting of a surfactant and a polymer characterised by opposite charges, to obtain a stable foam.
• U.S. Pat. No. 6,802,673 discloses an aqueous foaming additive consisting of an anionic surfactant and a ⁇ -naphthalene sulphonate formaldehyde condensate.
• U.S. Pat. No. 4,442,018 discloses the composition of an additive for the production of a stable foam in aqueous phase consisting of an acrylic acid polymer, a C12-C14 and C16 alcohol, a C4 and C5 alcohol, sodium lauryl sulfate or alpha-olefin sulphonate, and water.
• the present invention relates to the use as conditioning foaming additive of a salified alkyl ether sulphate having a straight or branched C7-C11 alkyl chain and a degree of ethoxylation ranging between 4 and 9 as conditioning agent able to generate foam during mechanised soil excavation with a TBM.
• the additive in liquid, paste or powder form, generates foam when added in percentages of 0.1-4% by weight to an aqueous solution used on the tunnel face to soften the soil and allow faster extraction, and in the conditioning chamber to maintain the stability of the tunnel face.
• the use of a salified alkyl ether sulphate having a branched C7-C11 alkyl chain and a degree of ethoxylation of 7-9 is preferred.
• the alkyl ether sulphate is preferably a sodium or potassium salt.
• the salified alkyl ether sulphate can be used in addition to an aqueous solution in a percentage by weight of 0.1-4.0%.
• the salified alkyl ether sulphate can also be used in admixture with one or more surfactants selected from acyl glutamates and alkyl polyglucosides, in particular in admixture with an acyl glutamate selected from cocoyl glutamate, lauroyl glutamate, myristoyl glutamate, capryloyl glutamate, caproyl glutamate and the sodium salts thereof or in admixture with an alkyl polyglucoside selected from decyl glucoside, capryl glucoside, lauryl glucoside and cocoyl glucoside. Lauroyl glutamate, in particular in the form of sodium salt, and capryl glucoside, are particularly preferred.
• the percentages by weight of the total surfactant(s) present in the conditioning additive can range from 30 to 100% for alkyl ether sulphate, 0 to 50%, preferably 5 to 50%, for acyl glutamates, and 0 to 50%, preferably 10 to 50%, for alkyl polyglucoside, obviously on the proviso that the total is 100.
• the surfactants according to the invention are classifiable as readily biodegradable according to the OECD 301 guidelines.
• the additives can also contain foam stabilisers able to increase the half-lives of the foams generated.
• the stabilisers can be biopolymers.
• biopolymers refers to polymers degradable due to the effect of micro-organisms such as bacteria, fungi or seaweed. They are mainly water-soluble polysaccharides able to increase the viscosity of an aqueous system in a pH range between 4 and 12.
• the preferred biopolymers are xanthan gum and guar gum.
• the additives are characterised by a lower ecotoxicological impact than the products commercially available and used in mechanised excavations.
• the foaming additive can also contain other compounds useful to deal with specific problems such as clogging due to clayey soils, to prevent high consumption of the cutters fitted in the cutterhead, or to reduce the quantity of soluble salts in the water present in the excavation soil.
• Column A shows the composition by weight expressed as a percentage of the formulation
• column B shows the weight percentage of the single compound as a percentage of the active content.
• the stability of the foam generated by an aqueous solution prepared by adding 2% by weight of foaming additive to 5000 g of water is evaluated.
• the stability is expressed as the half-life, which indicates the time required for the weight of the foam to halve.
• the test is conducted by evaluating the time in which water amounting to half the weight/volume of the foam is released in a 250 ml cylinder.
• the foam is formed by a generator that conveys the flow of liquid at a constant airflow into a glass ball mixer.
• Example 2 Conditioning Capacity of the Additives of Example 1
• the conditioning capacity of the additives of Example 1 was evaluated with a stabilised soil called “Vitali” (particle size 0.075-25 mm).
• the foam used to condition the matrix is generated from an aqueous solution prepared by adding 2% by weight of foaming additive to 5000 g of water.
• the foam is formed by a generator that conveys the flow of liquid at a constant airflow into a glass ball mixer.
• the evaluation involves adding the foams generated with the additives to three 11 kg samples of aggregate, and homogenising the mixture in an IMER 5140 cement mixer (drum capacity 138 lt) for 5 minutes.
• the matrix conditioning is scored as a slump class.
• Table 3 The results are set out in Table 3:
• Example 3 Composition of Alcohol-Free Additive Having a Lower Degree of Ethoxylation (Present in Commercial Additives)
• Sample no. 4 was formulated without straight Cl 2-C14 alcohol ethoxylate (2-3 moles of ethylene oxide) and sodium sulphate.
• the stability of the foam generated by an aqueous solution prepared by adding 2% by weight of foaming additive to 5000 g of water is evaluated.
• the stability is expressed as the half-life, which indicates the time required for the weight of the foam to halve.
• the test is conducted by evaluating the time in which water amounting to half the weight/volume of the foam is released in a 250 ml cylinder.
• the foam is formed by a generator using a constant airflow.
• the data demonstrate an increase in the stability of the foam.
• the foaming additives have the following compositions:
• Sample no. 7 was formulated without straight C12-C14 alcohol ethoxylate (2-3 moles of ethylene oxide) and sodium sulphate, which is always present as foam generator in commercial products.
• the stability of the foam generated by an aqueous solution prepared by adding 2% by weight of foaming additive to 5000 g of water is evaluated.
• the stability is expressed as the half-life, which indicates the time required for the weight of the foam to halve.
• the test is conducted by evaluating the time in which water amounting to half the weight/volume of the foam is released in a 250 ml cylinder.
• the foam is formed by a generator using a constant airflow.
• Example 6 Aquatic Toxicity of an Additive of Example 1 by Comparison with a Commercial Additive
• Example 7 Aquatic Toxicity of the Additives of Example 1 by Comparison with a Commercial Additive
• Example 8 Acute Toxicity in Fish of the Additive of Example 3
• Example 9 Acute Toxicity in Fish of the Additive of Example 4
• the foaming additives called “Polyfoamer ECO 100” and “sample 7” were evaluated to establish their acute toxicity in fish (OECD 203).

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Soil Sciences (AREA)
• Mining & Mineral Resources (AREA)
• Organic Chemistry (AREA)
• Materials Engineering (AREA)
• Environmental & Geological Engineering (AREA)
• Geochemistry & Mineralogy (AREA)
• Geology (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Emulsifying, Dispersing, Foam-Producing Or Wetting Agents (AREA)
• Soil Conditioners And Soil-Stabilizing Materials (AREA)
• Excavating Of Shafts Or Tunnels (AREA)
• Compositions Of Macromolecular Compounds (AREA)

Applications Claiming Priority (3)

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Citations (7)

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• 2018
  • 2018-07-23 IT IT102018000007438A patent/IT201800007438A1/it unknown
• 2019
  • 2019-07-23 CA CA3107241A patent/CA3107241A1/fr active Pending
  • 2019-07-23 SG SG11202100497YA patent/SG11202100497YA/en unknown
  • 2019-07-23 PT PT197525611T patent/PT3827066T/pt unknown
  • 2019-07-23 PL PL19752561.1T patent/PL3827066T3/pl unknown
  • 2019-07-23 US US17/262,389 patent/US11697768B2/en active Active
  • 2019-07-23 AU AU2019308812A patent/AU2019308812A1/en active Pending
  • 2019-07-23 DK DK19752561.1T patent/DK3827066T3/da active
  • 2019-07-23 ES ES19752561T patent/ES2977190T3/es active Active
  • 2019-07-23 WO PCT/IB2019/056273 patent/WO2020021445A1/fr unknown
  • 2019-07-23 EP EP19752561.1A patent/EP3827066B1/fr active Active

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